Models for MIMD Machines

This paper describes two simple models for estimating the processing times of algorithms run on MIMD (Multiple Instruction Multiple Data) machines. The first model is developed from very elementary queueing concepts. The second uses the critical path through a PERT-diagram-arrangement of the algorithm's tasks. The models require far less effort than either benchmarking or detailed simulations. We envision them being used in all but the very final stages of the search for, and design of, good combinations of algorithms and MIMD machines.